Latching means



July 9, 1968 5. J, BlCKHAM 3,391,603

LATCHING MEANS Filed June 22, 1967 3 Sheets-Sheet 1 INVENTOR. SYDNEYJAMES BICKHAM ATTORN EYS S. J. BICKHAM LATCHING MEANS July 9, 1968 3Sheets-Sheet 2 Filed June 22, 1967 INVENTOR. SYDNEY JAMES BICKHAM FIG.2

BY o 0/ ATTORNEYS July 9, 1968 5. J. BICKHAM 3,391,603

LATCHING MEANS Filed June 22, 1967 3 Sheets-Sheet 5 INVENTOR' SYDNEYJAMES BI CKHAM ATTOR N EYS United States Patent 3,391,603 LATCHING MEANSSydney James Bickham, Oakville, Ontario, Canada, assignor to OrendaLimited, Toronto, Ontario, Canada Filed June 22, 1967, Ser. No. 654,3008 Claims. (Cl. 89-1.819)

ABSTRACT OF THE DISCLOSURE In a missile launching system including aframe extending in the missile launching direction and a missile supportelement pivoted to the frame about a transverse axis, the missilesupport element being swingable from 3. normal supporting position to alimit position clear of the missile path, automatic latching meanscarried by the frame are operable by the swingable support element forpositively retaining the latter when it has moved to the limit position.The latching means comprises a trip member in the form of a pivotedbell-crank, which is engaged by means carried on the support element foroperating a latch bolt.

BACKGROUND OF THE INVENTION (1) Field of invention This inventionrelates to latching means and is concerned particularly with automaticlatching mechanisms for use in a system comprising a stationary framestructure and an element which is movable relatively to the structurealong a predetermined path to a limit position defined by a stop.

The invention is applicable to a missile launching system of the kindcomprising a frame structure extending in the missile launchingdirection, a rear missile support, a front missile support, which ispivoted to the frame structure so as to be swingable from a normalsupporting position to a limit position at which it is clear of themissile path, and a latching mechanism for retaining the front supportfor preventing rebound of the latter when it reaches the limit position.

(2) Description of prior art The closest known prior art is No.2,604,014, Walker et al., which discloses a missile launching system ofthe kind referred to above. The latching mechanism is springoperated,however.

Spring-operated latching mechanisms for use in apparatus having anelement which is movable from a first, operative position to a second,latching position are well known. When the operational speed of themovable element is very high, however, it is not possible to construct aspring-operated latch which will react quickly enough to engage themovable element before the latter has re bounded from the limit stop. Inthe missile launching system with which the applicant is most concerned,the movable element to be retained has an extremely high operationalspeed, and a spring-operated latching mechanism as disclosed in theabove mentioned patent would be quite unsuitable to retain the element.

SUMMARY OF THE INVENTION The present invention provides an automaticlatching mechanism which is operated by means carried by the movableelement so that the speed of the latching operation is always in directrelationship to the operating speed of the element. The latchingmechanism basically comprises a transverse pin mounted on the movableelement and movable therewith, a latch bolt which is movable between afirst, unlatching position and a second, latching position, the latchbolt when in its latching position extending across the path of movementof the pin and 3,391,533 Patented July 9, 1968 ice being engageabletherewith, a pivoted trip member having a first radial arm extendingacross the path of movement of the pin, and a second radial arm, andmeans providing a lost motion connection between the second radial armand the latch bolt, the trip member being operable by engagement of thepin with the first radial arm to move the latch bolt into its second,latching position.

BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the invention asapplied to a missile launching system will now be described, by way ofexample, with reference to the accompanying drawings in which:

FIGURE 1 is a general perspective view of a missile launcher in which alatching mechanism in accordance with the invention is incorporated;

FIGURE 2 is an enlarged side elevation, in section, of the front missilesupport of the system shown in FIGURE 1, FIGURE 2 showing details of thelatching mechanism; and

FIGURE 3 is a front elevation, partly in section, of a detail of FIGURE2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGURE 1, amissile 10 is supported by a launch beam 11 forming part of a stationaryframe structure mounted on a trailer vehicle 12. The launch beam 11 is atubular truss which is adjustable in elevation and train to lay themissile in launching attitude. Rear launch fittings or missile supportssuch as indicated at 13 support the tail end of the missile 10 andlocate it. A front launch fitting or missile support 14 is pivotallylocated at the front end of the launch beam 11 and engages a cooperatingportion (not shown) on the missile body. The missile support 14 ismovable relatively to the stationary frame structure along apredetermined path, so that upon firing the support 14 swings forwardlyand downwardly as the missile moves off the launcher, to a limitposition shown in full lines in FIGURE 2, the limit position beingdefined by stop means 54 mounted on the stationary frame structure. Theswingable missile support 14 is retained at the limit position by alatching mechanism 15.

Referring now more particularly to FIGURES 2 and 3, the launch beam 11terminates at its forward end in a transversely angled end plate 16which is welded thereto. Spaced-apart lugs 17 are welded to the endplate 16 and are bored to receive pins 18 for pivotally supporting thefront missile support 14. The front missile support 14 comprises ahollow, welded sheet metal structure having at one end a sector-shapedcap 19 which engages a co-operating fitting (not shown) on the missile.The welded sheet metal structure diverges and is bifurcated to form twolegs 20 each terminating in a solid pintle block 21. The pintie blocks21 are adapted to receive the removable pivot pins 18 in threaded andlocked engagement therewith in a well-known manner. An internaltransverse plate 22 forms a croth 23 between the legs 20 and alsoreinforces the structure of the support 14. The legs of the frontmissile support 14 are bored transversely, adjacent to the crotch 22, toreceive coaxial tubular housings 24 welded in place. The housings haveinner ends 25 which are angled to conform to the inner surfaces of thelegs 20. The outer ends 26 of the housings are square and proud of theouter surfaces of the legs. The housings 24 each carry a compositeresilient bush 27 comprising inner and outer metallic sleeves betweenwhich an elastomeric material is sandwiched, shock absorbing bushes ofthis type being well known in the art. The bushes 27 support a pin orshaft 28 which is retained therein and is also restrained from rotationby roll-pins 29, which pass through bores in the outer ends of the pin28 and the inner sleeves of the resilient bushes 27. A flat 30 ismachined on the portion of the pin 28 exposed between the legs .20.Bolted to the end plate 16 of the launch beam 11 is an assemblyconsisting of an open-bottomed box bracket 31, a welded structurecomprising a mounting plate 32, a top plate 33 and two side plates 34.One end of the top plate 33, remote from the mounting plate 32, iscontoured to receive a cylindrical latch bolt housing .35 which is alsowelded to the side plates 34. The side plates have stilteners 36 weldedto their outer surfaces adiacent the lower edges. The latch bolt housmghas a bore 37 in which a latch bolt 38 is slidably mounted for movementbetween a first, unlatching position, shown in ghost lines in FIGURE 2,and a second, latching position, shown in full lines in FIGURE 2. Thelatch bolt 38 has a lower end having a chamfered front face 39 and arear flat face 40. The upper end of the latch bolt 38 is provided with acap 41 secured by means of a bolt 42. the cap retaining a bufier ring 43of resilient material. This construction limits the extension of thelatch bolt on the lower end of its housing.

A spring-loaded ball catch 44 in threaded engagement in a bore in theupper end of the latch bolt housing 35, is adapted to engage a detent 45in the latch bolt to releasably retain the latch bolt in its first,unlatching position. A rectangular slot 46 through the latch bolt istraversed by a pin 47 supported in bores through the sides of the slot,a co-operating slot 48 being formed in the wall of the bolt-housing andopening into a space 49 within the box bracket 31.

A trip member constituted by a belt crank lever 51 is pivotally mountedfor movement about a transverse axis on a pin 52 passing through boresformed in the side walls 34 of the bracket 31. The bell crank lever hasa first, lower, radial arm 53 which extends across the path of movementof the pin 28, and a second, upper. radial arm 50 which extends throughslots 46 and 48 to engage the pin 47. The stop means 54, determining thelimit position of the swingable supporting element 14, comprises aresilient butter block bolted to the end plate 16 adjacent to its loweredge.

The operation of the latching means in the missile launching system willnow be described.

With a missile mounted on the launcher, the front launch fitting 14 isin the up position as shown in FIG. 1, and the missile is located by itsrear support fittings 13. The latch bolt 35 is manually withdrawn and ismaintained in the unlatching position by ball catch h 44. It is notessentially that the bolt be set in this manner in order for themechanism to operate, but in practice it is preferable to have the latchbolt cocked because of the accelerations involved. The bell-crank lever51 will assume the position shown in ghost lines in FIG. 2.

When fired, the missile 10 moves very rapidly 01f the launcher and thefront launch fitting 11 is caused to rotate to the downward position.The fiat 30 on pin 28 clears the lower end of the latch bolt 38 butengages the lower radial arm 53 of the bell crank. thereby rotating itin an anti-clockwise direction as viewed in FIG. 2 until the frontlaunch fitting is brought up against the stop formed by the buffer block54. Rotation of the bell crank 51 is translated into downward movementor the latch bolt 38 through engagement of the upper radial arm 50 withthe pin 47. The latch bolt extends to a latching position (shown in fulllines in FIG. I) where its flat surface 40 will engage the pin 28 as thelaunch fitting rebounds from the buffer block. The fitting is therebyprevented from further rotation on the rebound and possible contact withthe rear of the missile body. The pin 28 will rebound from the flatsurface 40 of the latch bolt, but the lost motion connection between theradial arm and the upper portion of the latch bolt prevents theadditional mass of the bell crank lever trom immediately adding to therebound forces acting on the latch bolt. Side forces are thus induced inthe latch bolt which increase friction between it and its housing, to adegree that the momentum of the latch bolt is damped.

if the latch bolt is not set in the unlatching position before tiring ofthe missile, the engagement of the pin b8 with the chamfered end surface39 of the bolt will cause the latter to be urged upwardly into itshousing to clear the tlat 30 on the pin. Further rotation of the launchlitting will initiate the locking action already delcribed.

The form of the invention hereinbefore described is given by way ofexample only, and it will be understood that the latching mechanism maybe altered and adapted to many applications, other than missilelaunching systems, without departing from the Spirit of the invention.

What i claim as my invention is:

ll. in a system comprising a stationary structure and lm element whichis movable relatively to the structure along a predetermined path to alimit position defined by a stop means on the stationary structure,latching means comprising a transverse pin mounted on the movablelllement and movable therewith; a latch bolt; means mounting the latchbolt in the structure for movement between a tirst, unlatching positionand a second, latchlng position. the latch bolt when in the latchingposition extending across the path of movement of the pin and beingengageable therewith; a trip member carried by the structure, the tripmember being pivoted about a transverse axis; the trip member having afirst radial arm extending across the path of movement of the transversepin, and a second radial arm; and means providing a lost motionconnection between the second radial arm and the latch bolt, the tripmember being operable by engagement of the pin with the first radial armto move the latch bolt into its second, latching positron.

Latching means according to claim 1, including a bolt housing carried bythe stationary structure, the latch bolt being mounted in the bolthousing and slidable therein between its first and second positions.

.3. lLatching means according to claim 2, wherein the bolt housingincludes a spring-loaded ball catch which booperates with a detent inthe latch bolt to retain the bolt in its first position.

Latching means according to claim 2, wherein th latch bolt has achamfered front face engageable with the pin to permit movement of thepin past the bolt in the one direction towards the limit position.

5. In combination with a missile launching system inbinding a framestructure and a missile supporting element pivoted to the framestructure about an axis which is transverse to the missile launchingdirection so that the supporting element is swingable along an arcuatepath from a normal supporting position to an angularly ltpaced limitposition: stop means mounted on the frame llIIllCtUIe for determiningthe limit position, and latchlng means for positively retaining thesupport element ln the limit position, the latching means comprising apin mounted on the support element and extending transversely thereto,the pin being movable with the support element along an arcuate path; alatch bolt; means mounting the latch bolt on the frame structure formovement between a first, unlatching position and a second, latchingposition, the latch bolt when in the latching position extending acrossthe path of movement of the pin and being engageable therewith; a tripmember carried by the structure, the trip member being pivoted about atransverse axis, the trip member having a first radial arm extendingacross the path of movement of the transverse pin. and a second radialarm; and means providing a lost motion connection between the secondradial arm and the latch bolt, the trip member being operable byengagement of the pin with the first radial arm to move the latch boltinto its second, latching position.

llli

llto

6. The combination claimed in claim 5, in which the latch bolt isslidable in a bolt housing mounted on the frame structure, the bolthousing including a springloaded ball catch which cooperates with adetent in the latch bolt to retain the bolt in its first position.

7. The combination claimed in claim 6, wherein the latch bolt has achamfered front face engageable with the pin to permit movement of thepin past the bolt in the one direction towards the limit position.

8. The combination claimed in claim 5, wherein the ends of thetransverse pin are retained in resilient bushes mounted in the missilesupporting element, each References Cited UNITED STATES PATENTS 7/1952Walker et al. 89l.819 1/1956 Bush 24463 SAMUEL W. ENGLE, PrimaryExaminer.

